JP4266721B2 - Polyurethane-polyurea dispersion - Google Patents

Abstract

Post-crosslinkable polyurethane-polyurea dispersion comprises polyisocyanate, polymeric polyol having average molar weight of 400- 6000, optionally mono- or polyalcohol or mono- or polyamine having average molar weight of up to 400, at least one blocking agent, and at least one compound chosen from compounds having at least one ionic or potentially ionic group and nonionically hydrophilicizing compounds. Post-crosslinkable polyurethane-polyurea dispersion comprises polyisocyanate, polymeric polyol having average molar weight of 400-6000, optionally mono- or polyalcohol or mono- or polyamine having average molar weight of up to 400, at least one blocking agent, and at least one compound chosen from compounds having at least one ionic or potentially ionic group and nonionically hydrophilicizing compounds. At least 20 wt.% of the blocking agent comprises aralkylamine. Independent claims are included for the following: (1) method for producing one of paints and coating compositions, sizes and glass fiber sizes; (2) coating compositions, sizes and glass fiber sizes, comprising the post-crosslinkable polyurethane-polyurea dispersion; (3) substrate coated with coating composition; and (4) glass fibers sized with size comprising the dispersion.

Description

  The present invention relates to polyurethane-polyurea dispersions having isocyanate groups blocked with aralkylamines (hereinafter referred to as PU dispersions) and their preparation and use.

  In the coating of substrates, solvent-containing binders are increasingly being replaced by environmentally friendly aqueous systems. In particular, due to its superior properties, the role of binders based on polyurethane-polyurea dispersions is increasing. For many applications, 2K (two component) systems are generally used which are composed of OH functional binders and polyisocyanates (which may or may not be blocked). In addition, 1K (one component) self-crosslinkable PU dispersions described, for example, in US Pat. No. 4,387,181 (US-A 4 387 181) contain blocked isocyanate groups and isocyanate-reactive groups in many fields. Is very interested in. Heat treatment of the system after application results in a highly crosslinked coating, but little or no chemical crosslinking with the coated substrate. In contrast, PU dispersions with blocked isocyanate groups and no significant amount of isocyanate-reactive groups can be crosslinked with the applied or incorporated substrate under heat load. . This type is called a post-crosslinkable PU dispersion and is described, for example, in German Offenlegungsschrift 19548030.

  The main compounds used for blocking isocyanates and polyisocyanates are, for example, European Patent Publication Nos. 0576952, 0566953, 159117, US Pat. No. 4,482,721, WO 97/12924, Alternatively, ε-caprolactam, butanone oxime, malonate, secondary amine, triazole derivative, and pyrazole derivative described in European Patent Application Publication No. 0744423 and German Patent Application Publication No. 19548030.

Secondary amine blocking agents containing aralkyl-substituted amines are known, for example, from EP-A-0096210. However, the use of such amines in aqueous systems, in particular postcrosslinkable PU dispersions, is not known from EP-A-0096210.
Preparation of aqueous post-crosslinkable PU dispersions usually involves the use of prior art blocking agents such as epsilon-caprolactam and butanone oxime.

For postcrosslinkable PU dispersions having isocyanate groups blocked with ε-caprolactam, a baking temperature of about 160 ° C. is usually used, but postcrosslinkable PU dispersions using butanone oxime as a blocking agent are , And can be deblocked at a temperature lower by 10 to 20 ° C. However, at these temperatures, the desired properties are no longer achieved with a large number of coatings. Moreover, at high deblocking or drying temperatures, binders or coatings often cause undesirable thermal yellowing. In addition, these deblocking temperatures are currently very costly and require the development of postcrosslinkable PU dispersions containing blocked isocyanate groups that crosslink with the corresponding substrate at lower temperatures than butanone oxime. It has been.
A further disadvantage of prior art postcrosslinkable PU dispersions is their poor hydrolytic stability in films and coatings.
German Patent Application Publication No.19548030 European Patent Application Publication No. 0096210

  Accordingly, an object of the present invention is to provide an isocyanate group that is blocked with a blocking agent that has a significantly lower deblocking temperature compared to the prior art, and further provides a coating with high hydrolysis resistance. It is to provide a post-crosslinkable PU dispersion.

In the present invention, it has been found that a PU dispersion having an isocyanate group blocked with an aralkylamine satisfies the above profile.
The present invention comprises the following components:
A1) polyisocyanate,
A2) a polymer polyol having an average molecular weight of 400 to 6000,
A3) optionally mono- or polyalcohol or mono- or polyamine having an average molecular weight of up to 400,
A4) at least one blocking agent, wherein at least 20% by weight is composed of aralkylamines,
And
A5) compounds having at least one ionic or latent ionic group and / or
A6) at least one compound selected from polyoxyalkylene ethers having at least one hydroxyl group or amino group as a nonionic hydrophilic compound;
In addition, a post-crosslinkable aqueous PU dispersion comprising an alkylamine blocked isocyanate, optionally composed of a diluent, a solvent, and an adjuvant, is provided.
The dispersion polymers obtained from components A1) to A6) no longer contain any isocyanate-reactive groups.

BEST MODE FOR CARRYING OUT THE INVENTION

  All numerical ranges, amounts, values, and percentages used herein (for substance amounts, reaction times and temperatures, quantity ratios, molecular weight values, and others in the following part of the specification) are other Unless specifically stated otherwise, the term “about” can be read as if preceded, even if the term “about” is not explicitly indicated with these values, amounts, and ranges.

The solids content of the post-crosslinkable PU dispersion of the present invention can vary within the range of 10 to 70% by weight. The solid content of the post-crosslinkable PU dispersion of the present invention is preferably 20 to 60% by mass, particularly preferably 25 to 50% by mass. As a proportion of the total composition, the organic solvent fraction is preferably less than 15 wt%, particularly preferably less than 10 wt%, very preferably less than 5 wt%.

In the present invention, a latent ionic group is a group that can form an ionic group.
Preferably, the PU dispersion of the present invention comprises 10-40% by weight A1), 30-90% by weight A2), 0-30% by weight A3), 1-20% by weight A4), 0-15. Containing a mass% of ionic or potentially ionic compounds A5), and 0-40% by mass of compounds A6), the total of the components being 100% by mass.

More preferably, the PU dispersion of the present invention comprises 10-30% by weight A1), 30-80% by weight A2), 0-20% by weight A3), 1-15% by weight A4), 0- It contains 8% by weight of ionic or potentially ionic compound A5) and 0-35% by weight of compound A6), the total of the components being 100% by weight.
Most preferably, the PU dispersion is 15-30 wt% A1), 30-70 wt% A2), 0-10 wt% A3), 1-10 wt% A4), 0-8 wt% Of ionic or potentially ionic compounds A5), and 5-30% by weight of compound A6), the total of the components being 100% by weight.

  Suitable diisocyanates (A1) are basically those having a molecular weight of 140 to 400 having aliphatic, cycloaliphatic, araliphatic and / or aromatic linked isocyanate groups (eg 1,4-diisocyanato Butane, 1,6-diisocyanatohexane (HDI), 2-methyl-1,5-diisocyanatopentane, 1,5-diisocyanato-2,2-dimethylpentane, 2,2,4- and 2,4 , 4-trimethyl-1,6-diisocyanatohexane, 1,10-diisocyanatodecane, 1,3- and 1,4-diisocyanatocyclohexane, 1,3- and 1,4-bis- (isocyanate) Natomethyl) -cyclohexane, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 4,4'-diisocyanatodicyclohexylmethane, 1-isocyanato-1-methyl- 4 (3) -iso Anatomethylcyclohexane, bis- (isocyanatomethyl) -norbornane, 1,3- and 1,4-bis- (2-isocyanato-2-propyl) -benzene (TMXDI), 2,4- and 2,6-di Isocyanatotoluene (TDI), 2,4′- and 4,4′-diisocyanatodiphenylmethane, 1,5-diisocyanatonaphthalene, or any desired mixture of such diisocyanates).

  These are preferably polyisocyanates or polyisocyanate mixtures of the aforementioned kind which exclusively have aliphatic and / or cycloaliphatic bonded isocyanate groups. Highly preferred starting components (A1) are polyisocyanates and polyisocyanate mixtures based on HDI, IPDI and / or 4,4'-diisocyanatodicyclohexylmethane.

For example, J.A. Prakt. Chem. 336, 1994, pp. 185-200, having a uretdione, isocyanurate, urethane, allophanate, biuret, iminooxadiazinedione, and / or oxadiazinetrione structure, simple The desired polyisocyanates prepared by modification of aliphatic, cycloaliphatic, araliphatic and / or aromatic diisocyanates are more suitable as polyisocyanates (A1).
At least 5%, preferably at least 10%, particularly preferably at least 15% of the isocyanate groups of the polyisocyanate (A1) of the PU dispersion according to the invention are in blocked form.

  Polymer polyols (A2) with a molecular weight range of 400-6000 are the usual ones that have been used in polyurethanes and have an OH functionality of at least 1.6-4 (eg, polyacrylates, polyesters, polylactones, polyethers, polycarbonates, Polyester carbonates, polyacetals, polyolefins, and polysiloxanes). Polyols with a molecular weight range of 600-2500 and OH functionality of 2-3 are preferred.

  Suitable polycarbonates having hydroxyl groups can be obtained by reaction of carbonic acid derivatives (eg diphenyl carbonate, dimethyl carbonate or phosgene) with diols. Suitable such diols are, for example, ethylene glycol, 1,2- and 1,3-propanediol, 1,3- and 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol. , Neopentyl glycol, 1,4-bishydroxymethylcyclohexane, 2-methyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, dipropylene glycol, polypropylene glycol, dibutylene glycol Polybutylene glycol, bisphenol A, tetrabromobisphenol A, and lactone-modified diols. The diol component is preferably 40-100% by weight hexanediol, preferably 1,6-hexanediol, and / or hexanediol derivatives (preferably having either an ether or ester group in addition to the terminal OH group (E.g., by reaction of 1 mol hexanediol with DE 1770245 with at least 1 mol, preferably 1-2 mol caprolactone, or the formation of di- or trihexylene glycol by etherification of hexanediol itself). Product). The preparation of such derivatives is disclosed, for example, in German Offenlegungsschrift 1570540. The polyether-polycarbonate diols described in DE 3717060 can also be used.

  The hydroxy polycarbonate should be substantially linear. However, they may optionally be slightly branched by incorporation of multifunctional components, especially low molecular weight polyols. For example, glycerol, trimethylolpropane, 1,2,6-hexanetriol, 1,2,4-butanetriol, trimethylolpropane, pentaerythritol, quinitol, mannitol, sorbitol, methylglycoside, and 1,3,4,6 -Dianhydrohexitol is suitable for this purpose.

Suitable polyether polyols are polytetramethylene glycol polyethers known per se in polyurethane chemistry and can be prepared, for example, by tetrahydrofuran polymerization by cationic ring opening.
Other suitable polyether polyols are, for example, polyethers such as polyols prepared from styrene oxide, propylene oxide, butylene oxide or epichlorohydrin, in particular propylene oxide, using an initiator molecule.

  Suitable polyester polyols are, for example, the reaction products of polyvalent, preferably divalent, and optionally further trihydric alcohols with polybasic, preferably dibasic carboxylic acids. For the preparation of the polyesters, it is also possible to use, instead of the free polycarboxylic acids, the corresponding polycarboxylic anhydrides or the corresponding polycarboxylic esters of lower alcohols or mixtures thereof. The polycarboxylic acid may be aliphatic, alicyclic, aromatic and / or heterocyclic, optionally substituted and / or unsubstituted, for example with a halogen atom.

Monofunctional alcohols and monoamines are suitable compounds (A3) for terminating the polyurethane prepolymer. Preferred monoalcohols are aliphatic monoalcohols having 1 to 18 C atoms (eg, ethanol, n-butanol, ethylene glycol monobutyl ether, 2-ethylhexanol, 1-octanol, 1-dodecanol, or 1-hexadecane). Nord etc.). Preferred monoamines are aliphatic monoamines such as diethylamine, dibutylamine, ethanolamine, N-methylethanolamine, or N, N-diethanolamine.
Also suitable as component (A3) are polyols, aminopolyols or polyamines having a molecular weight of less than 400 as described in the corresponding literature.

Examples of preferred components (A3) are:
a) Alkanediol (ethanediol, 1,2- and 1,3-propanediol, 1,4- and 2,3-butanediol, 1,5-pentanediol, 1,3-dimethylpropanediol, 1,6 -Hexanediol, neopentyl glycol, cyclohexanedimethanol, and 2-methyl-1,3-propanediol),
b) ether diols (such as diethylene diglycol, triethylene glycol, or hydroquinone dihydroxyethyl ether),
c) General formulas (III) and (IV):
_{HO- (CH 2) x -CO-} O- (CH 2) y -OH (III)
_{HO- (CH 2) x -O-} CO-R-CO-O- (CH 2) x -OH (IV)
Wherein R is an alkylene or arylene group having 1 to 10 C atoms, preferably 2 to 6 C atoms,
x is 2-6,
y is 3-5)
Ester diols represented by (for example, δ-hydroxybutyl-ε-hydroxycaproate, ω-hydroxyhexyl-γ-hydroxybutyrate, β-hydroxyethyl adipate, and bis (β-hydroxy-ethyl) terephthalate), and
d) Polyamines (ethylenediamine, 1,2- and 1,3-diaminepropane, 1,4-diaminobutane, 1,6-diaminohexane, isophoronediamine, 2,2,4- and 2,4,4-trimethylhexa Isomeric mixtures of methylenediamine, 2-methyl-pentamethylenediamine, diethylenetriamine, 1,3- and 1,4-xylylenediamine, α, α, α ′, α′-tetramethyl-1,3- and 1, 4-xylylenediamine, and 4,4-diaminodicyclohexylmethane). Diamines suitable in the present invention also include hydrazine, hydrazine hydrate, and substituted hydrazines (eg, N-methyl hydrazine, N, N′-dimethyl hydrazine, and homologs thereof), and acid dihydrazide, adipic acid, β-methyl Adipic acid, sebacic acid, hydroacrylic acid, and tetraphthalic acid, semicarbazide alkylene hydrazide (for example, β-semicarbazide propionic acid hydrazide (for example, German Patent Application Publication No. 1770591)), semicarbazide alkylene-carbazine ester (for example, 2-semicarbazide ethylcarbazine ester (for example, German Patent Application Publication No. 1918504) or aminosemicarbazide compound (for example, β-aminoethylsemicarbazide-carbonate (for example, German Patent Application Publication No. 1902931)) Ah .

（式中、R¹、R²、R³は、同一でも異なっていてもよく、水素、C₁〜C₄アルキル、C₆〜C₁₀シクロアルキル、好ましくは水素を示し、
R⁴は、C₁〜C₄アルキル、C₆〜C₁₀シクロアルキル、またはC₁〜C₁₄アラルキル、好ましくはメチル、エチル、イソプロピル、およびtert−ブチル、特に好ましくはtert−ブチルを示し、
xは1、2、3、4、または5の数を示す）
に相当する。 The aralkylamine of component A4) has the formula (V)

(Wherein R ¹ , R ² and R ³ may be the same or different and each represents hydrogen, C ₁ -C ₄ alkyl, C ₆ -C ₁₀ cycloalkyl, preferably hydrogen;
R ⁴ represents C ₁ -C ₄ alkyl, C ₆ -C ₁₀ cycloalkyl, or C ₁ -C ₁₄ aralkyl, preferably methyl, ethyl, isopropyl and tert-butyl, particularly preferably tert-butyl,
x represents the number 1, 2, 3, 4, or 5)
It corresponds to.

  Examples of blocking agents A4) are: N-methyl-, N-ethyl-, N- (iso) propyl-, Nn-butyl-, N-iso-butyl-, N-tert-butyl -Addition products of benzylamine or 1,1-dimethylbenzylamine, N-alkyl-N-1,1-dimethylmethylphenylamine, benzylamine and compounds having activated double bonds (such as malonate), N, Mention may be made of N-dimethylaminopropylbenzylamine and other unsubstituted or substituted benzylamines and / or dibenzylamines containing tertiary amino groups. Of course, mixtures of these amines with each other and / or mixtures of these amines with other blocking agents can also be used. These include, for example, alcohol, lactam, oxime, malonate, alkyl acetoacetate, triazole, phenol, imidazole, pyrazole, and amines such as butanone oxime, diisopropylamine, 1,2,4-triazole, dimethyl-1,2,4 -Triazole, imidazole, diethyl malonate, ethyl acetoacetate, acetone oxime, 3,5-dimethylpyrazole, ε-caprolactam, or any desired mixture of these blocking agents. N-aralkylamines (N- (iso) propylbenzylamine, Nn-butylbenzylamine, N-isobutylbenzylamine, N-tert-butylbenzylamine, etc.) are preferably used as blocking agent A4). A more preferred blocking agent A4) is N-tert-butylbenzylamine.

Suitable ionic or potentially ionic compounds A5) that can be used in addition to or instead of nonionic compounds A6) are, for example, mono and dihydroxy carboxylic acids, mono and diamino carboxylic acids, mono and dihydroxy sulfones Acids, mono- and diaminosulfonic acids, mono- and dihydroxyphosphonic acids, or mono- and diaminophosphonic acids and their salts, such as dimethylolpropionic acid, hydroxypivalic acid, N- (2-aminoethyl) -β-alanine, 2 -(2-amino-ethylamino) -ethanesulfonic acid, ethylenediamine-propanesulfonic acid or ethylenediamine-butanesulfonic acid, 1,2- or 1,3-propylene-diamine-β-ethylsulfonic acid, lysine, 3,5 -Implementation of Diaminobenzoic Acid, European Patent Application No. 0916647 Hydrophilizing agent as described in Example 1 and its alkali metal and / or ammonium salts, addition products of sodium bisulfite and 2-butene-1,4-diol, polyether sulfonate, 2-butenediol and NaHSO ₃ Propoxylated addition products (eg German Offenlegungsschrift 2446440, pages 5-9, formulas I-III), as well as cationic groups, can be used as hydrophilic components A structural unit (for example, N-methyldiethanolamine). Preferred ionic or potentially ionic compounds A5) are those containing carboxyl or carboxylate groups and / or sulfonate groups and / or ammonium groups. Particularly preferred ionic compounds A5) are those containing carboxyl and / or sulfonate groups as ionic or potentially ionic groups (N- (2-aminoethyl) -β-alanine salts, 2- (2-amino) Ethylamino) ethanesulfonic acid salts, hydrophilizing agent salts described in Example 1 of EP 0916647, and dimethylolpropionic acid salts.

  The hydroxy component in components (A2), (A3), and (A5) can include double bonds that can be derived from, for example, long chain aliphatic carboxylic acids or fatty alcohols. For example, functionalization with olefinic double bonds is possible by incorporation of allyl groups or acrylic or methacrylic acid and their respective esters.

（式中、R¹およびR²は、互いに独立してそれぞれ、酸素および／または窒素原子を含み得る1〜18個のC原子を有する二価の脂肪族、脂環式、または芳香族基を示し、
R³は、ヒドロキシル末端ではない、ポリエステルまたは好ましくはポリエーテルを示し、R³は、特に好ましくはアルコキシ末端ポリエチレンオキシドの基を示す。）
で示される化合物も含まれる。 Furthermore, the PU dispersion of the present invention may contain a nonionic hydrophilic compound (A6) (for example, a polyoxyalkylene ether having at least one hydroxyl group or amino group). These polyethers contain structural units derived from ethylene oxide in a proportion of 30% to 100% by weight. Suitable polyethers include not only linear polyethers having a functionality between 1 and 3, but also the general formula (VI):

Wherein R ¹ and R ² are each independently a divalent aliphatic, alicyclic, or aromatic group having 1 to 18 C atoms that may contain oxygen and / or nitrogen atoms. Show
R ³ represents a polyester or preferably a polyether which is not hydroxyl-terminated, R ³ particularly preferably represents an alkoxy-terminated polyethylene oxide group. )
The compound shown by these is also included.

  Nonionic hydrophilic compounds A6) include, for example, monovalent polyalkylene oxide polyether alcohols containing an average of 5 to 70, preferably 7 to 55, ethylene oxide units per molecule (alkoxyls of suitable starting molecules). (For example, Ullmanns Encyclopaedie der technischen Chemie, 4th edition, volume 19, Verlag Chemie, Weinheim, pp. 31-38). Examples of suitable starting molecules are saturated monoalcohols (methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, isomeric pentanols, hexanol, octanol and nonanol, n-decanol, n -Dodecanol, n-tetradecanol, n-hexadecanol, n-octadecanol, cyclohexanol, etc., isomeric methylcyclohexanol or hydroxymethylcyclohexane, 3-ethyl-3-hydroxymethyloxetane, or tetrahydrofurfuryl Diethylene glycol monoalcohol ether (eg, diethylene glycol monobutyl ether); unsaturated alcohol (allyl alcohol, 1,1-dimethylallyl alcohol, or oleyl) Alcohol, aromatic alcohol (phenol, isomeric cresol or methoxyphenol, araliphatic alcohol (benzyl alcohol, anisyl alcohol, cinnamyl alcohol, etc.); secondary monoamines (dimethylamine, diethylamine, dipropylamine) , Diisopropylamine, dibutylamine, bis- (2-ethylhexyl) -amine, N-methyl- and N-ethylcyclohexylamine, or dicyclohexylamine, and heterocyclic secondary amines (morpholine, pyrrolidine, piperidine, or 1H-pyrazole, etc.).

Preferred starting molecules are saturated monoalcohols and diethylene glycol monoalkyl ethers. It is particularly preferred to use diethylene glycol monobutyl ether as the starting molecule.
Particularly suitable alkylene oxides for the alkoxylation reaction are ethylene oxide and propylene oxide, which can be used in any order or mixture for the alkoxylation reaction.

  The polyalkylene oxide polyether alcohol is either a pure polyethylene oxide polyether or a mixed polyalkylene oxide polyether in which at least 30 mol%, preferably at least 40 mol% of alkylene oxide units consist of ethylene oxide units. Preferred nonionic compounds are monofunctional mixed polyalkylene oxide polyethers containing at least 40 mol% ethylene oxide units and up to 60 mol% propylene oxide units.

  It is also possible to use a combination of an ionic hydrophilizing agent (A5) and a nonionic hydrophilizing agent (A6) for hydrophilizing the postcrosslinkable PU dispersion of the present invention. In this case, it is preferable to use a combination of an anionic hydrophilizing agent (A5) and a nonionic hydrophilizing agent (A6). Overall, it is preferred to exclusively use the nonionic hydrophilizing agent A6) for the preparation of the postcrosslinkable PU dispersions according to the invention.

  The aqueous polyurethane dispersion of the present invention is, for example, D.I. Prepared in a known manner from the prior art as summarized in the review of Dieterich (D. Dieterich, Prog. Org. Coatings, 9, 281, (1981)). The components A2) and / or A3) and / or A6), the blocking agent A4) and the low molecular weight chain extender A3 using a solvent which can be separated again later if desired. ) And / or A5) to produce a polyurethane. Suitable solvents are the usual paint solvents known per se (eg ethyl acetate, butyl acetate, 1-methoxy-2-propyl acetate, 3-methoxy-n-butyl acetate, acetone, 2-butanone, 4-methyl -2-pentanone, cyclohexanone, toluene, xylene, chlorobenzene, mineral spirits, especially mixtures containing relatively highly substituted fragrances (eg Solvent Naphtha Solvesso ™ (Exxon Chemicals, Houston, USA), Cypar ™ (Shell Chemicals, Eschborn, Germany), Cyclo Sol ™ (Shell Chemicals, Eskborn, Germany), Tolu Sol ™ (Shell Chemicals, Eskborn, Germany), Shellsol ™ (Shell Chemicals, Eskborn, Germany) Germany)), carbonate (dimethyl carbonate, die Carbonates, 1,2-ethylene carbonate, and 1,2-propylene carbonate), lactones (such as β-propiolactone, γ-butyrolactone, ε-caprolactone, and ε-methylcaprolactone), propylene glycol diacetate, diethylene glycol Dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol ethyl- and butyl ether acetate, N-methylpyrrolidone and N-methylcaprolactam, or any desired mixture of such solvents). Preferred solvents are acetone, 2-butanone, and N-methylpyrrolidone. Acetone is particularly preferred.

In a further step, the groups that can be neutralized can then be converted into the salt form or transferred to the aqueous phase, if desired. Depending on the degree of neutralization and the content of ionic groups, the dispersion can be very finely dispersed to have a substantially solution appearance, but a formulation of very coarse particles is also possible, It is equally stable as well.
However, an average particle size of less than 300 nm is preferred because emulsification of the polyisocyanate is improved, thereby improving the quality of the coating.

  Preferably, the polyol components A2), A3) and A6) and the blocking agent A4) are first introduced and reacted with the polyisocyanate A1). Thereafter, any further hydroxy-functional component A3) is added and the reaction mixture is reacted without the addition of a solvent to produce a polyurethane prepolymer. The prepolymer is dispersed by the addition of water. The optional amino-functional component A3) and / or A5) is then added, for example in the form of an aqueous solution.

The solids content of the post-crosslinkable PU dispersion of the present invention can vary within the range of 10 to 70% by weight. The solid content of the post-crosslinkable PU dispersion of the present invention is preferably 20 to 60% by mass, particularly preferably 25 to 50% by mass. As a ratio of the whole composition, the solvent ratio is preferably less than 15% by mass, more preferably less than 10% by mass, and most preferably less than 5% by mass.

  The PU dispersions of the present invention are used in combination with suitable reaction partners containing isocyanate-reactive groups in aqueous binders such as polyurethane dispersions and / or polyacrylate dispersions and / or mixtures or hybrids thereof. Can do. Further suitable reaction partners include low molecular weight amines, which can be treated in an aqueous solution to give a thermally crosslinkable coating composition, which can be treated from the aqueous phase. Furthermore, the PU dispersions of the present invention can also be incorporated into 1K binders such as polyurethane dispersions and / or polyacrylate dispersions and polyurethane-polyacrylate hybrid dispersions.

The post-crosslinkable PU dispersions of the present invention are used for the purpose of painting, sizing or impregnating substrates containing hydrogen atoms that are reactive towards isocyanate groups, for example, without adding further reaction partners You can also
Similarly, the present invention provides the use of the PU dispersions of the present invention in paint and paint compositions. A post-crosslinkable polyurethane-polyurea dispersion can be added to the formulation to produce a sizing agent.

  The postcrosslinkable PU dispersions of the present invention are used alone or in combination with other aqueous binders for the preparation of coating compositions. Such aqueous binders can be composed, for example, of polyester, polyacrylate, polybutadiene, polyvinyl acetate, polyepoxide, or other polyurethane polymers. For example, a combination with a radiation curable binder described in European Patent Application No. 0753531 is also possible.

  The postcrosslinkable PU dispersion of the present invention is preferably used as a binder in paints and adhesives. Paints based on the composition of the present invention can be applied to any desired substrate (for example, metal, wood, glass, glass fiber, carbon fiber, stone, ceramics, optionally coated with a conventional primer before painting) Minerals, concrete, a wide variety of hard and soft plastics, woven and non-woven fabrics, leather, paper, hard fibers, straw, and bitumen). Preferred substrates are glass fiber, carbon fiber, metal, woven fabric and leather. One particularly preferred substrate is glass fiber.

The post-crosslinkable PU dispersions of the present invention can be used alone or as auxiliaries and additives known in the paint art (eg, nonionic and / or ionic thickeners, fillers for paint manufacture) Pigments, waxes, textures, dyes, solvents, leveling agents, crosslinkers, and the like).
The coating material can be applied in a known manner (eg brushing, pouring, knife coating, spraying, rolling or dipping). The coating can be dried at room temperature or elevated temperature or by baking up to 200 ° C.

  The PU dispersions of the present invention can be stored and transported and processed at any subsequent point in time. Depending on the polyurethane composition chosen, paints with different properties are obtained. Thus, soft adhesive coatings, thermoplastic and elastomer products with a wide range of hardness can be obtained from glass hardness thermosetting plastics.

  It is also preferred to use the postcrosslinkable PU dispersions of the present invention in sizing agents, particularly glass fiber sizing agents. Thus, a post-crosslinkable polyurethane-polyurea dispersion can be added to the formulation to produce a sizing agent.

The PU dispersions of the present invention can be used alone in the sizing agent or preferably other binders (eg polyacrylate dispersions, polyurethane-polyacrylate hybrid dispersions, polyvinyl ether or polyvinyl ester dispersions, polystyrene or polyacrylonitrile). For example, a dispersion or the like, or in combination with a crosslinking agent such as a blocked polyisocyanate (crosslinking agent) and an amino crosslinking resin such as a melamine resin.
Furthermore, it is possible to add further crosslinking agents before application. Suitable crosslinkers for this purpose are preferably hydrophilic or hydrophilized polyisocyanate crosslinkers.

For sizing preparation, the postcrosslinkable PU dispersions of the present invention are generally used as binding and crosslinking components, which are emulsifiers, additional film-forming resins, adhesion promoters, lubricants, and auxiliaries (eg, wet Agent or antistatic agent). Adhesion promoters, lubricants and auxiliaries, methods for preparing sizing, methods for sizing glass fibers, and subsequent processing of glass fibers are known; L. Loewenstein, “Manufacturing Technology of Continuos Glass Fibers”, Elsevier Scientific Publishing Corp. Listed in Amsterdam, London, New York, 1983.
The present invention also provides sizing glass fibers comprising the PU dispersion of the present invention.

  Known glass types used for glass filament manufacturing (such as E, A, C, and S glass) and other products known per se in glass fiber manufacturing are suitable as sized glass fibers . Among the glass types for continuous glass filament production, E glass fiber is most important for plastic reinforcement due to its absence of alkali, high tensile strength, and high elastic modulus.

  A number of thermoplastic and thermosetting polymers can be used as the matrix polymer. Examples of suitable thermoplastic polymers include: polyolefins (such as polyethylene or polypropylene), polyvinyl chloride, addition polymers (such as styrene / acrylonitrile copolymers, ABS, polymethacrylate or polyoxymethylene), aromatics And / or aliphatic polyamides (such as polyamide 6 or polyamide 6,6), polycondensates (polycarbonate, polyethylene terephthalate, liquid crystal polyaryl esters, polyarylene oxides, polysulfones, polyarylene sulfides, polyaryl sulfones, polyether sulfones, Polyaryl ethers or polyether ketones), or polyadducts (such as polyurethane). Examples that may be mentioned as suitable thermosetting polymers include: epoxy resins, unsaturated polyester resins, phenolic resins, amine resins, polyurethane resins, polyisocyanurates, epoxide / isocyanurate blended resins, Furan resin, cyanurate resin, and bismaleimide resin.

The mechanical properties of the postcrosslinkable PU dispersion were measured on independent films produced as follows.
A film applicator consisting of two polishing rolls that can be set at precise intervals has a release paper inserted in front of the rear roll. The distance between the paper and the front roll was adjusted using a thickness gauge. This distance corresponds to the undried film thickness of the resulting coating and can be adjusted to the desired additional amount of each coating. The painting can also be carried out continuously with two or more coatings. To apply each coating, the product (the aqueous formulation is pre-adjusted to a viscosity of 4500 mPa by addition of ammonia / polyacrylic acid) is poured into the nip between the paper and the front roll, and the release paper is The film was drawn vertically downward and a corresponding film was formed on the paper. If two or more coatings were applied, each coating was dried and the paper was reinserted.

The 100% modulus of a film with a thickness exceeding 100 μm was measured according to DIN 53504.
The average particle size (indicating average value) of the PU dispersion was measured by laser correlation spectroscopy (instrument: Malvern Zetasizer 1000, Malver Inst. Limited).
Film storage under hydrolysis conditions is carried out according to DIN EN12280-3. The mechanical properties of these film samples are measured after storage for 24 hours under standard conditions (20 ° C., humidity 65%) according to DIN 53504.

Example 1 (invention) :
128.8 g of polyether Desmophen ™ 3600Z (Bayer AG, Germany, propylene oxide-based difunctional polyether with an average molecular weight of 2000 (OH number = 56)), 25.6 g of Polymer ™ L400 (Bayer AG, Germany) , Propylene oxide based bifunctional polyether with an average molecular weight of 561 (OH number = 200), 86.4 g of Polyether LB25 (Bayer AG, Germany, ethylene oxide / propylene oxide based unit with an average molecular weight of 2250 (OH number = 25) Functional polyether) and 21.5 g of N-tert-butylbenzylamine are introduced into a container and heated to 70 ° C. 100.01 g of Desmodur ™ W (Bayer AG, Germany) is then added over 5 minutes. The mixture is then stirred at 75 ° C. for 45 minutes. After the addition of 5.2 g of trimethylolpropane, the reaction mixture is stirred at 75 ° C. until the theoretical NCO value is reached and cooled to 60 ° C. Disperse by addition of 527.0 g of water (20 ° C.) over 10 minutes. Immediately after dispersion, a solution of 1.70 g hydrazine monohydrate, 10.2 g isophorone diamine, and 178.6 g water was added at 40 ° C. over 5 minutes. The mixture is then stirred at 40 ° C. for 3 hours. This gives a storage stable aqueous PU dispersion having a solids content of 33.0% and containing blocked isocyanate groups.

Example 2 (comparison) :
128.8 g of polyether Desmophen ™ 3600Z (Bayer AG, Germany, propylene oxide-based difunctional polyether with an average molecular weight of 2000 (OH number = 56)), 25.6 g of Polyether L400 (Bayer AG, Germany, average molecular weight 561 (OH number = 200) propylene oxide based bifunctional polyether), 86.4 g Polyether LB25 (Bayer AG, Germany, average molecular weight 2250 (OH number = 25) ethylene oxide / propylene oxide based monofunctional poly Ether), and 14.9 g epsilon caprolactam are introduced into a container and heated to 70 ° C. 100.01 g of Desmodur ™ W (Bayer AG, Germany) is then added over 5 minutes and the reaction mixture is heated to 100 ° C. Then, stir at 100 ° C. for 45 minutes. After the addition of 5.2 g of trimethylolpropane, the reaction mixture is stirred at 100 ° C. until the theoretical NCO value is reached and cooled to 60 ° C. Disperse by addition of 527.0 g of water (20 ° C.) over 10 minutes. Immediately after dispersion, a solution of 1.70 g hydrazine monohydrate, 10.2 g isophorone diamine, and 178.6 g water was added at 40 ° C. over 5 minutes. The mixture is then stirred at 40 ° C. for 3 hours. This gives a storage stable aqueous PU dispersion having a solids content of 34.6% and containing blocked isocyanate groups.

  The results listed in Table 1 show that using the inventive PU dispersion of Example 1 provides substantially higher hydrolysis resistance than the prior art PU dispersion (Example 2). Furthermore, the dispersion of Example 1 due to the lower deblocking temperature of the blocking agent N-tert-butylbenzylamine compared to the dispersion of Example 2 comprising a prior art blocking agent (caprolactam). It is shown from the tensile strength and elongation at break that significantly higher mechanical properties are obtained after 10 minutes drying time at 125 ° C.

The present invention and preferred embodiments thereof are as follows.
[1]
A1) polyisocyanate,
A2) a polymer polyol having an average molecular weight of 400 to 6000,
A3) optionally mono- or polyalcohol or mono- or polyamine having an average molecular weight of up to 400,
A4) at least one blocking agent, wherein at least 20% by weight is composed of aralkylamines,
And
A5) a compound having at least one ionic group or a latent ionic group;
A6) with nonionic hydrophilic compounds
At least one compound selected from
A post-crosslinkable polyurethane-polyurea dispersion composed of
[2]
The post-crosslinkable polyurethane-polyurea dispersion according to item [1], wherein at least 5% of the isocyanate groups of component A1) are in a blocked form.
[3]
The post-crosslinkable polyurethane-polyurea dispersion according to item [1], wherein the solid content of the dispersion is 10 to 70% by mass.
[4]
The post-crosslinkable polyurethane-polyurea dispersion according to item [1], wherein the solvent ratio of the dispersion is less than 15% by mass of the total composition.
[5]
The post-crosslinkable polyurethane-polyurea dispersion according to item [1], wherein aralkylamine is used as a blocking agent.
[6]
The post-crosslinkable polyurethane-polyurea dispersion according to item [1], wherein secondary benzylamine is used as a blocking agent.
[7]
The post-crosslinkable polyurethane-polyurea dispersion according to item [1], wherein N-tert-butylbenzylamine is used as a blocking agent.
[8]
A method for producing one of paint and coating compositions comprising adding the post-crosslinkable polyurethane-polyurea dispersion according to item [1] to a formulation.
[9]
A method for producing a sizing agent, comprising adding the post-crosslinkable polyurethane-polyurea dispersion according to the above item [1] to a formulation.
[10]
A method for producing a sizing agent for glass fiber, comprising adding the post-crosslinkable polyurethane-polyurea dispersion described in the item [1] to a blend.
[11]
A coating composition comprising the post-crosslinkable polyurethane-polyurea dispersion according to item [1].
[12]
A sizing agent comprising the post-crosslinkable polyurethane-polyurea dispersion according to item [1].
[13]
A glass fiber sizing agent comprising the post-crosslinkable polyurethane-polyurea dispersion described in the item [1].
[14]
A substrate coated with a coating composition containing the post-crosslinkable polyurethane-polyurea dispersion described in the item [1].
[15]
The glass fiber which gave the size containing the post-crosslinkable polyurethane-polyurea dispersion as described in said [1].
While the invention has been described in detail above for purposes of illustration, such details are for purposes of illustration only and are intended and intended to be limited by the scope of the invention, except as may be limited in the claims. It should be understood that variations can be made by those skilled in the art without departing from the invention.

Claims (1)

A1) polyisocyanate,
A2) an average molecular weight of Po triol 400 to 6000,
A3) optionally mono- or polyalcohol or mono- or polyamine having an average molecular weight of up to 400,
A4) at least one blocking agent, wherein at least 20% by weight is composed of aralkylamines,
And
A5) a compound having at least one ionic group or a latent ionic group;
A6) A post-crosslinkable polyurethane-polyurea dispersion composed of at least one compound selected from at least one hydroxyl group or polyoxyalkylene ether having an amino group as a nonionic hydrophilic compound.